What have they done? 29 in 24 timeline...

So here's the deal, I have been set with the task of re-editing a client's master tape for distribution. They don't have any original footage due to a fallout with the original editor. What they do have is a 23.976 fps master tape hd that has been converted to prores 422 to edit on fcp. Some of the transition exterior shots were shot in 29.97 and were thrown into the timeline without being interpolated to 23.976 and thus are choppy.

I have to get that footage to play smoothly, and I don't think the usual 29.97 -> 23.976 conversion process will work due to the footage technically being in 23.976 already.

Is it possible to get that footage to play smoothly in a 29.97 timeline again, or were frames chopped out never to be seen again?